Varicose veins, because of their cosmetically undesirable consequences, are a condition for which patients have sought surgical treatment. Surgical treatment of varicose veins typically involves the removal of a substantial portion, if not all, of the varicose vein, from the body. The most frequently removed vein is the large saphenous vein, which returns blood from the ankle upward along the leg.
Removal of the saphenous vein typically involves exposing it with an incision in the groin area, and severing the saphenous vein at its junction with the deeply located femoral vein. The saphenous vein is also exposed near the ankle or the knee by another incision. The prior art teaches various surgical techniques for stripping varicose veins, each with its own benefits and disadvantages. The primary objective with all stripping procedures is to ensure complete removal of the vein, while minimizing trauma to the surrounding perivenous tissues.
One prior art stripping technique involves the use of a ring, sized slightly larger than the diameter of the vein trunk, placed around the trunk and passed downward, using a rigid rod, until the ring encounters a vein branch. As it travels downward, the ring loosens the perivenous tissue from the vein. An incision is then made in the skin at the point at which the ring is palpated to expose the vein. The vein is brought to the surface and ligated. Now the loosened portion may be removed. The procedure repeats for the next vein portion and continues until the desired length of the vein has been removed. This method is disadvantageous because it requires a number of small incisions in order to divide and ligate the branches. These effects are cosmetically undesirable. Moreover, the technique is time consuming and tedious because it requires a number of different sized rings, which must be separately installed to efficiently strip varying diameters of vein segments as the operation proceeds. Although the use of the ring to loosen the vein results in effective saphenectomy, or vein removal, there is increased trauma to the perivenous tissue and thus increased post-operative discomfort to the patient. Multiple branches of the saphenous vein may necessitate additional incisions to divide the branches. The method also results in fracture of the main vein trunk causing excessive bleeding and difficulty in removing the main trunk. External stripping is thus outmoded.
Prior art techniques also include internal stripping, which involves cannulation, or insertion into the lumen of the vein, of a tool. The tool typically takes the form of a blunted string-like wire which is semi-flexible to permit navigation of the vein lumen. The wire is usually inserted into the vein from below and passed upward in order to minimize interference from the valves within the vein. For example, the Babcock/Meyers intraluminal stripping method involves the installation of a stripping head on the end of the rod once it emerges from the distal end in the vein. The stripping head is acorn-shaped and provided with a blunt edge which removes the vein by pure traction, in a sense, ripping the vein out by force. The stripping head is then pulled downward by traction on the wire and strips the vein from the surrounding perivenous tissue. Vein branches are usually torn of as they are encountered by the stripper. With this method, as a result of the taper of the saphenous vein from a large diameter down to a small diameter as one proceeds from the groin to the ankle, the entire saphenous vein trunk accumulates at the stripper head as it is drawn downward. The passage of this "bundle" of accumulated vein tissue downward through the perivenous tissues results in significant trauma and post-operative discomfort to the patient.
Vein stripping by invagination is another internal stripping technique of the prior art illustrated in FIGS. 1A-1D. This technique involves the attachment of the vein wall to a suitably shaped rod or braided wire 70. After the rod or wire 70 is cannulated, the distal end of the vein is attached to it with suture material 74. The distal end of the vein is then drawn closed with a suitable knot 78 in the sutures as shown in FIG. 1B. The vein wall is then inverted upon itself, quite similar to the way a sock would be turned inside out, so that the outer surface 80 of the vein travels downward within the vein lumen and becomes an inner 82 surface as shown in FIG. 1C. The venous tissue thus peels away from surrounding perivenous tissue 84, minimizing trauma to the patient.
Vein stripping by invagination has two major disadvantages. First, the taper of the saphenous vein results in the large upper end of the vein being inverted down through the narrower lower portion. Referring to FIG. 1D, as the stripping proceeds, travel of the large inverted end of the vein may meet with increased resistance within the vein lumen. Moreover, constriction 90 of the vein lumen, because of thick-walled or spastic portions, will obstruct travel of the inverted portion, thereby complicating to surgical procedure. Typically, invaginate stripping may be limited to small portions of the saphenous veins, instead of removing the vein in a single stripping step. For example, perforate-invaginate stripping (PIN) as described by Goren and Yellen in the Journal of Vascular Surgery, Volume 20, Number 6, pp. 970-77, involves a specially designed instrument that enables perforation of the vein wall from within and invagination of a portion of the saphenous vein through the perforation. One end of the tool is provided with a blunt head for grasping the traction sutures. The opposite end of the tool is provided with a groove for indicating the orientation of an angled segment of the tool which is rotated within the vein and used to perforate the vein wall. The short segment of the vein is then removed after it is inverted and invaginated upon itself.
The second major disadvantage of this stripping techniques is that the inverted portion of the vein may tear during the stripping operation. Frequently, strong branches of the main trunk of the saphenous vein will not sever as the main trunk is inverted and peeled away from the branch. Instead, the inverted portion of the vein tears because the junction between the branch and the main trunk is stronger than inverted portion. The severed portion of the inverted vein remains attached to the stripping rod or wire and will emerge at the lower incision in the vein when the rod or wire is withdrawn. The remaining portion, however, must first be located, and then retrieved by other stripping methods, usually involving additional incisions in the skin, additional scars on the body, and increased trauma to the patient.
Thus, while stripping by invagination results in less trauma than the Babcock/Meyers method, it is less effective in facilitating successful stripping of varicose veins. For this reason, use of the invaginate method is less favored in the vascular surgery field than the Babcock/Meyers stripping technique. There is thus a need for a surgical instrument and technique which improves the effectiveness of the invaginate vein stripping method and which facilitates easy change-over to the Babcock/Meyers type stripping operation in the event of unsuccessful stripping using the invaginate stripping method.